Key-operated adding machine



July 4, 1950 E 1 THElsEN 2,513,532

KEY-OPERATED ADDING MACHINE Filed Nov. 24, 1947 Patented July 4, 1950 UNITED STATES PATENT OFFICE KEY-DPERATED ADDING MACHINE Eugene JacobTheisen, East Orange, N. J.

Application November 24, 1947, Serial No. 787,774

' (c1. zas- 82) 1 Claim. 1

matical calculations, such as addition, subtrac- 7 tion, and multiplication.

A further object is to provide a small, simple device which is constructed to be manufactured economical-ly and is composed of afew simple readily and easily related parts which can be Y manipulated by anyone without any special knowledge of mechanism..

A still further object is to provide a device which can be manipulated by the thumb and index and forefingers of thehand and held in the hand by the remaining fingers.

Yet another object is to provide a device which can be held in the hand and manipulated by the ngers of that hand without the necessity Aof taking the eyes from the figures entering into the calculation. y

1Further and more specific objects, features and advantages will more clearly appear from a consideration of the detailedl specification hereinafter set forth, especially when taken in connection with the accompanying drawings which illustrate a present preferred formv which the invention. may assume and which form part of the specification.v

In brief and general terms, the invention includes a small casing` which may be 3 inches high, 31/2 inches deep, vand 41/2 inches wide containing a series of numeral wheels rotatable on a shaft fixed within and across the casing. Also `within the casing isa travelling carriage suitably supportedV for.v sliding movement `across the` casing on guide bars and'V associatedr with means to latch the carriage in successive predetermined positions in relation to the numeral wheels.

On the carriage is disposed ay gear sector with a finger operated mechanism and disposed below and adapted to engage a numeral wheel, with which the carriage may be positionally related., to advance said wheel five positions for each operation and this finger-operated mechanism involves Va linger key extending preferably laterally from the casing and to be operated by the thumb of the hand grasping the casing. On top of the carriage are two finger keys which when depressed respectively by the index and foreflngers of the hand grasping the casing lare adapted'respectively to depress elements toy advance the numeral `wheel one position for each operation thereof or to retract the numeral wheel' one position for each operation'. The'casing is, of course, constructed with suitable slots along which the finger keys move and through which they extend.

The mathematical principle on which this device operates is the well-known one which concerns the adding of a problem column by :column by adding five to the -wheel 'for each digit in the column (except Zero) and then adding or subtracting the amounts by which the digits respectively exceed or fall short of the value live. For instance if a column had six numbers in it as follows: 4, 5, 7, 9*, 3, 2 then -we depress the key actuating the gear sector six times thus putting the number thirty into the mechanism. After this is entered then `we actuate the other two keys to add or subtract the required amounts aswill be explained in detail later. After one column has been gured thus, the carriage is moved to align the keys and their associated parts with the next wheel and so on until each column has been scanned by this method and the final result appears on the usualY opening in the casing.

The present preferred form which the invention may assume is illustrated in the drawings of which- Fig. 1 is a side elevation of the machine with the casingr broken away;

Fig. 2 is a plan view of the gear sector and operating key taken on the line 21-21 of Fig. l.; and

the casing broken away.

Referring now merely to the speciiic form of the invention shown in the drawings, which is only one form which it may assume, it is to be noted that there is provided a casing 12a within which there is fixed a shaft I2 which extends across the casing just to the rear of an extended view opening 9 therein. On this shaft I2 are rotatably disposed a series of numeral wheels 6 representing the various numerical columns within the capacity of the machine. Each Wheel Ei has teeth such as l5 and I8 and between each pair of teeth is an area Il on which are marked numerical values as usual. These related wheels 6 are associated with carry-over mechanism to be latex` described.

In order to operate the numerical wheels 5, there is provided a movable carriage in the form of a somewhat U-shaped casting I9 which is mounted slidably on guide rods or bars 20 fixed between the walls of the casing 12a and extending thereacross. A lower limb of this carriage supports rotatably a gear sector 4 on a shaft 4a and this sector is provided with five teeth 5. This sector is provided with a sloping. slot 8 in which rides a pin on the end of a rod 2 which is jointed at 3 and whichv rod 2 is operated by a finger key I on the end of the rod 2 which extends through a suitable slot (not shown) inthe front wall of the casing. A spring 'l is provided in association with rod 2 to return it to normal position when the key is released of actuating pressure by the nger of the operator. The slope of the slot 8 is such as to move the sector 4 clockwise when the key I is pushed in and moves it a half turn. When released from pressure the spring 'I returns the sector to normal position by continuing its motion in the same direction tol complete its full rotation. A single depression of key I will turn the sector 4 and advance the numeral wheel 6 under which the sector 4 is disposed an amount equal to five numbers.

Disposed on the upper limb of the carriage` I9 are two keys I3 and I6. The key i3 has an operating rod I4 retractible by a spring Ida, and dependent to a point above a tooth I5 of the numeral wheel 6 with which the carriage may be related. The depression of key I3 `is adapted to advance said wheel one position to add one to theconiputation. The key I6 is provided with an operating rod I'I retracted by a spring Ia and dependent to a point just above a tooth I8 of the said wheel 6, and the single depression of key I6 will move said wheel one position backward thereby subtracting one number from the computation. The rods I4 and I1 extend through slots (not shown) in the upper wall of the casingy so`that they may be moved across the casing with the carriage I9as the actuating elements thus described are' moved laterally to be associated with one or another of the numeral wheels 6.

In order readily to move the carriage and its associated operating elements from one numerical denominational wheel to another I have disposed a roller 2| on the upper limb of the carriage I9 under the upward impulsion of springs 22 to tend to seat itself in indentations on a rack plate 23 which is fastened to the under side of y the top ofthe casing I2a by means of screws 24.

These indentations are so disposed thatwhen the roller 2I is disposed in one of them the carriage I 9 and the cooperating actuating elements are f disposed in operative relation to a particular numerical wheel 6 and its teeth. The carriage and its associated parts may be moved by hand by merely pushingl laterally on the carriage against the resistance of the roller springs 22 until the desired position is reached.

In `order to hold the machine conveniently in the hand a pair of strap loops are provided as shown in Fig. 1 at the upper right corner of the casing I 2a which is Athe position most suitable to enable the third and fourth lingers of the hand to b e slipped therein and enable the thumb to operate the key I, the index finger to operate the key I3, and the middle finger to operate the key I6. After suitable practice, it is clearly evident that the operator may operate these keys without looking at the machine and thus be enabled to keep his eyes and his mind on the figures under consideration. .Y y

The carry over mechanism is actuated as follows: l

' Each number lwheel 6 has holes 33 on the right side thereof (Fig. l). Each wheel 6, in the position of the number 9, hasa plug 28 actuated by a spring and extendingv through vthe wheelv 6. It extends'out of the face of the wheel to the right about 3A; of the distance to the number Wheel 6 on itsuright and extends out to the left of the wheel '6 about A1/2 the distance to the number wheel 6 on the left. Between the wheels 6 and fixed to the shaft I2 are a plurality of plates 32 extending from the shaft I2 at the position where the View opening 9 is located and to aboutlfialf` the distancefrom the shaft I2 to the facesV ofl the number wheels 6. There is also a 4 plate 32 to the right of the first number wheel 6. Plug 28 being at the position on the wheel where the number 9 is painted, .contacts platet32., when the ligure 9 of its number wheel moves away from the view opening 9 up or down. Plugs 28 are disposed at an angle through the number wheels, lowest (toward shaft I2) on the right side in order to strike plate 32, and highest on the left and then once again for the digit 4 in the column side of the wheels 6 in order to clear the plate 32 on the left side. On contacting plates 32, plugs 28 are pushed to the left through the wheels 6 by reason of the projection (to the left) on plate 32, as shown in Fig. 3 (shaded markings between the number wheels and on the right of theiirst number wheel appearing in Fig. 3) extending .very close to the right side of the number wheels.

In moving to the left, plugs 28 imbed themselves into one of the holes 33 in the number wheel to the left. This connects the rst two number wheels together for a single spacing, vsince as plugs 28 reach the end ofthe extension or pro-v jection of plate 32, the spring around each plug within the wheel 6, brings the plug back to its original position. y

To position each wheel in propery numberindicating position in the view opening 9 there are provided projecting tips 25 on springs in Shaft I2 at places where each of the number wheels rotate arond shaft I2 and product a slight pressure against innerindentations 26 on'numberV wheels 6, thereby tending to holdl each wheel in proper number indicating position as it is moved around shaft I2. This also positions the wheels properly for suitable actuation by the sector 4 and the rods I4 and II above mentioned.

In considering the operation of the machine, let us assume we wish to add the following numbers:

We rst place the carriage with the cooperating parts in line with the units wheel 6. Since there are three digits in the units column to be computed, the key I is pushed in three times thus adding five three times to the wheels and showing 15 in the view opening. Then we press the key I3 twice to add the number 2 which is the amount by which the number '1 exceeds 5. Then we pressv key I6 once thus subtracting the number 1 representing the difference between 5 and 4 and then we press this key twice more to subtract two more units representing the `difference between 5V andfB. With practice, this is done almost autonriaticallyA and Without taking ones eyes olf the figures being added. After this computation the number 14 should show in the view opening 9.

The carriage is then moved to the left to position` the operating parts under the` tens wheel and the operation repeated, in this case byl pushing key I in twicesince there are, onlyL two digits f in the tens column, as we do not count the zero in this column. After this entry we depress the key IIBY three times for the digit 2 inthe column the parts under the hundreds columnnnumber wheel. 6,. A similaroperation is performedfby.

pressing the key I three times, the key AI3 four times for the 9 in the hundreds column and again three times for the 8 in the hundreds column. No key is pressed for the 5 in that column since that has already been entered and there is no need to add or subtract for its presence in the column. At the end of this series of movements the number will appear in the view opening 9 as 2274.

To clear the number wheels after a computation is completed, for instance to clear the number 2274 out of the wheels, it is merely necessary to align the carriage with the thousands wheel and depress the key I6 twice; then move the carriage in alignment with the hundreds Wheel and depress the key I6 twice; move the carriage under the tens wheel and depress the key I6 seven times; and then move the carriage under the units wheel and depress the key four times. Each such depression subtracts a 1 from the figure appearing in each column.

To multiply, since this is but another form of addition, if we wish to mulitply 12 by 6 We move the carriage under the units wheel and press the key I once for each units digit in the multiplicand; then move the carriage under the tens wheel and press the key I once for each tens digit in the multiplicand; then move the carriage under the units wheel and press key I3' once for each units digit in the multiplicand; then move the carriage under the tens wheel and press the key I3 once for each tens digit in multiplicand. Pressing the key I twice under the units wheel will place in the machine; pressing the key I once under the tens wheel will add making a total of in view; since 6 is one more than 5 pressing the key I3 twice under the units wheel will add 2 making a total of 62; then pressing the key I3 once under the tens wheel will add 10 making a total of 72, the correct answer. If we were multiplying 12 by 4 we would press the key I8 once for each unit in the units and tens column of the multiplicand since 4 is one less than 5. This routine is varied as the multiplier varies and diiers from 5 in accordance with the principles already set forth and which are clear upon careful consideration.

When an invoice is to be computed or audited and carries a discount of 2%, one unit (for each 1%) from each digit of the total, two spaces to the right of the last figure of the total, is per formed by key I6. Thus, if we have a discount of 2% to be deducted from a total of $16.96, We add two spaces to this figure and place the numbers 169600 in the machine appearing in the six wheels from the right. under the rst wheel we depress key I6 six times for the last digit in the real total which is 6 which brings the viewed total to 169594; then moving the carriage to the second wheel we depress the key I6 nine times for the second digit in the real total Iwhich is 9 thus bringing the viewed total to 169504; then we move the carriage under the third wheel and depress the key I6 six times for the third digit in the total bringing the viewed total to 168904; then moving the carriage under the fourth wheel We depress the key I6 once for the fourth digit in the total bringing the viewed total down to 167904. This operation has deducted 1% and is repeated to deduct another 1% giving a. final total of 166208 from which we get 16.62 after dropping the last two figures and allowing for the decimal points.

Many other operations, it will be apparent, can be performed on this simple device as the principles of its operation are carefully studied and Placing the carriage knowingly applied to the problems arising. Considering the subconscious operation of the machine, after sufficient practice, the actual consummation of the operations on the machine will be much faster than they appear to be from their description.

While the invention has been described in detail and shown with respect to the accompanying drawing, it is not to be limited to such details, since many changes and modiiications may be made in the invention Without departing from the spirit and scope thereof. Hence, it is desired to cover any and all forms and modifications of the invention which may come within the langauge and scope of the appended claim.

What I claim as my invention is:

In a device of the class described, a casing, a shaft fixed across within said casing, a series of toothed number Wheels rotatable on said shaft, a pair of guide bars supported across within said casing parallel to said shaft, a U-shaped carriage frame apertured along its base to slide on said bars to be positioned in alignment with any selected wheel, a rack on the upper inner wall of the casing, a spring-pressed roller on the upper limb of the carriage and engaging said rack to hold said carriage in said alignment, a vetoothed gear sector rotatable on the lower limb of the carriage, a manipulatable element connected to said sector and extending without the casing to be engaged by the thumb of the operator and to move said gear sector into engagement with the teeth of the selected wheel to move said wheel ve positions in one direction for each manipulation of said element, a second manipulatable element on the upper limb of the carriage and adapted, when operated, to engage the teeth of the selected wheel and move it one position in the same direction, said second manipulatable element extending without the casing and engageable by the index finger of the hand, a third manipulatable element adapted, when operated,

A-to engage the teeth of the selected wheel and move it one position in the opposite direction,

f said third element extending without the casing and adapted to be engaged by the middle finger of the hand.

EUGENE` JACOB THEISEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 93,350 Rossiter Aug. 3, 1869 380,718 Grissom Apr. l0, 1888 418,055 Phelps Dec. 24, 1889 488,206 Judd Dec. 20, 1892 555,218 Matsson Feb. 25, 1896 563,435 Wendt July 7, 1896 583,491 Labofish June 1, 1897 611,139 Orr Sept. 20, 1898 719,701 Steele Feb. 3, 1903 792,410 Gilbert June 13, 1905 865,200 Moore et al Sept. 3, 1907 899,482 Crawley Sept. 22, 1908 925,636 Horner June 22, 1909 1,120,138 Druschke Dec. 8, 1914 1,267,043 Arrington May 21, 1918 1,345,781 Hurley July 6, 1920 1,349,628 Phinney Aug. 17, 1920 1,954,598 Peterson Apr. 10, 1934 2,359,661 Moody Oct. 3, 1944 

